Sheet metal container with plastic closure



May 30, 1967 J. A. FOSTER SHEET METAL CONTAINER WITH PLASTIC CLOSURE 3 Sheets-Sheet 1 Filed Sept. 23, 1965 J. A. FOSTER SHEET METAL CONTAINER WITH PLASTIC CLOSURE- 3 Sheets-Sheet 2 ADVEIMTOKQ )1 CH. 79065} uu jq CqT-romzayw Filed Sept. 2, 1965 May 30, 1967 .1. A. FOSTER SHEET METAL CONTAINER WITH PLASTIC CLOSURE 5 Sheets-Sheet 5 Filed Sept. 2, 1965 v L IQVEMTQK 'cjohn m 21: Cdb% v Q-rTaRrOEIYL/ United States Patent 01 Filed Sept. 2, 1965, Ser. No. 489,787 13 Claims. (Cl. 220-60) This application is a continuation-in-part-of my copending applications Ser. Nos. 338,397, filed Jan. 17, 1964, now abandoned, and 425,470, filed Jan. 14, 1965, now abandoned.

The invention relates to a container of the type in which a skirt depending from the periphery of a cover of flexible plastic is telescoped with the end of a tubular sheet metal body and interlocked beneath a downwardly facing shoulder to fasten the cover securely to the body. the above resiliency of the plastic of the cover is utilized in a novel manner to secure the cover to the shoulder which is formed by bending a narrow portion of the metal at the end of the tubular body laterally and then reversely to form an end lip of curved cross-section to fasten the cover securely to the metal body but also to form a tight seal all A further object is to effect tight sealing of the cover on the body by wedging the body lip into a downwardly opening groove defined by the opposed surfaces of the two skirts.

Another object is to shape the shoulder engaging surface of the cover sk1rt in a novel manner to insure tight and uniform sealing in spite of dimensional variations in the cover and body resulting from manufacture of the cover and body by modern high production plastic molding and metal forming machinery.

The invention also resides in the manner of achieving the foregoing objects by forming the body lip as a rela tively flat hem.

Other objects and advantages of the invention will become apparent from the following detailed description taken in connection with the accompanying drawings, in which FIGURE 1 is a perspective view of a plastic covered sheet metal container embodying the novel features of the present invention.

FIG. 2 is a perspective View of one end of the container body.

FIGS. 3 and 4 are enlarged fragmentary sections taken along the lines 3-3 and 4-4 of FIGS. 1 and 2 respectively.

FIGS. 5 and 6 are similar cross-sections illustrating steps in the shaping of the container body.

FIGS. 7 and 8 are Views similar to FIGS. 1 and 2 showing on a ten size scale a preferred form of the invention.

FIGS. 9 and 10 are fragmentary cross-sections taken along the lines 99 and 10-10 of FIGS. 7 and 8 respectively.

FIG. 11 is a fragmentary section of the plastic cover taken along the line 11-11 of FIG. 7.

FIG. 12 is a fragmentary section taken along the line 12-12 of FIG. 7 in the course of assembly of the cover and container body.

3,322,299 Patented May 30, 1967 FIG. 13 is a fragmentary cross-sectional view similar to FIG. 11 showing a modified construction of the skirt on the plastic cover, the parts being shown as ten times actual size.

FIG. 14 is a fragmentary sectional view taken along the line 14-14 of FIG. 13.

FIG. 15 is a fragmentary perspective view of a part of FIG. 14.

end of a tubular body 12 and interlocked with a downwardly facing cover securely on the body. any desired cross-sectional shape,

adapted to be raised to expose an opening the container contents may be removed construction, stantially against the body as shown in FIG. 5 so as to leave the hem relatively flat with the edge 13 thereof spaced from the fold 22 a distance somewhat less than the spacing between the upper side IQ of the bead 16 and a surface 23 on the under side of the cover around the upper end of the skirt 11. Preferably, a narrow space 24 on the order of .O04.O=06 of an inch'is left between the two parts 25 and 26 that form the hem 21.

The width and radial depth of the peripheral groove 17 corresponds to that of the bead 16 as shown in FIG. 3. It is disposed in a position such that the raw edge 18 of the shoulder 13 is well exposed and adapted to bite into the softer plastic of the head on the upper side 19 thereof and thus increase the gripping action which holds the skirt securely interlocked with the end of the body.

The groove 17 is formed in a final station of the body forming machine after completion of the hemming, tubing, and seaming operations to convert the sheet metal blank into the form shown in FIG. 2. This is accomplished body and arranged for engagement with the full periphery of the can body. With the parts at rest in the positions shown in FIG. 5, the outer dies 28 are then collapsed inwardly thus stretching this metal inwardly beyond the hem shoulder to form the groove 17 to the desired depth when the dies reach the positions shown in FIG. 6. In this operation, the hem is engaged and bent inwardly somewhat by a surface 29 on the outer die leaving the outer surface of the hem diverging somewhat downwardly at a small angle and also offset inwardly as determined by the position of the inner die surface 31.

With the upper edge 32 of the laterally opening groove 17 disposed substantially at or above the shoulder 13, the edge 18 of the hem is exposed for certain engagement with the upper portion 19 of the head 16 in spite of the relative flatness and thinness of the hem. In view of the yieldable character of the plastic of the bead, the shoulder or edge 18 of the hem will bite or sink somewhat into the plastic and thus lock the bead and skirt effectually against outward movement. Such secure fastening is achieved automatically as an incident to placing the skirt 11 of the cover in alinement with the lip 22 of the body and pressing the cover downwardly until the top of the cover becomes substantially seated on the lip. In such telescoping, the lip of the body encounters the inwardly and upwardly converging surface 33 around the lower edge of the bead and earns the bead outwardly so as to allow the hem to pass. Then, as the hem edge 18 reaches the outwardly and upwardly diverging upper surface 19 of the bead, the skirt contracts and the bead snaps in beneath and into biting engagement with the hem edge as the flange 25 of the hem comes opposite the Wall 34.

In the final assembly shown in FIG. 3, the closed end of the hem fits closely in a downwardly opening groove defined by the wall 34 of the skirt 11 and an opposed substantially parallel wall 35 of a second and shorter inner skirt 36 integral with and depending from the cover Ml concentric with the outer skirt 11. Below the wall 35, the outer surface 37 of the inner skirt converges downwardly from an upper radius about equal to the internal radius of the bead 16. Thus, in the telescoping operation and after the hem lip 22 passes the bead, it engages the surface 37 which acts in the continued downward movement of the cover to guide the hem into its final position within the groove 34, 35. In this position, the outer surface of the skirt 11 is substantially flush with the outer surface of the body 12 by virtue of the offsetting of the hem inwardly from the latter surface at the bend 38.

A modified form of the invention is shown in FIGS. 7 to 11 in which the major parts are indicated by the same but primed reference numerals. In this instance, the shoulder 18 on the hem 21' is disposed on the inside of the body 12 and accordingly the long and short skirts ill and 36' are respectively disposed inside and outside of the body hem 21. The bead 16' is formed around the interior of the longer skirt 11' and its upper surface 43, which is engaged by the hem edge 18' in the final assembly, is wider horizontally than the thickness of the hem edge '13, is substantially flat in radial cross-section, and converges downwardly and outwardly at an angle of about 45 degrees. With this substantial inclination of the surface 43 relative to the horizontal, the inner skirt 11' will strip properly off from that portion of the die which forms the groove 34, 35' between the skirts Ill and 36 in the molding operation.

The thickness or of the hem is about .023 of an inch which is about three times the thickness (about .008 of an inch) of the metal 25, 26' forming the hem, these parts being disposed substantially parallel in the present instance. The recess 17' for effecting exposure of the hem edge 18 opens inwardly in this instance and is defined by an offset 49 which begins at a point 42 somewhat above the hem edge and diverges downwardly parallel to the upper surface 43 of the bead 16 and finally merges with the inner side wall 41 of the body 12. The downwardly opening groove which is defined by the skirt surfaces 34, 35' is disposed in vertical alinement with the 4 top surface 43 of the bead. The vertical width of the hem is correlated with the depth of this groove so that in the final assembly, the hem edge 18' engages the inner edge portion of the surface 43 as shown in FIG. 9.

To insure tight sealing between the cover and the hem, the hem and skirts are dimensioned to provide for wedging or pinching of the closed end portion of the hem in between the opposed walls 34', 35' of the groove defined thereby with the lip 22 of the hem disposed somewhat short of the bottom 23 of the groove. For this purpose, these walls converge slightly upwardly and toward each other and, at the points 47, 48 of engagement with the closed end portion of the hem, are spaced somewhat closer together as indicated at b (FIG. 11) than the radial thickness a (FIG. 10) of this portion of the hem, the difference being a few thousandths of an inch. Thus, the second skirt 36' serves not only as a lateral backing for maintaining the body lip 22 positioned properly relative to the skirt 11 and the bead 16' but also coacts with the latter in providing two effective seals at 47 and 48 near the lip of the container and all around the sides of this lip in spite of dimensional variations that may occur in high production manufacture of the engaging portions of the metal and plastic.

As before, the lower surface 44 of the bead 16' is inclined at a substantial angle and positioned for engagement with the lip 22' of the hem as the cover is pressed onto the hemmed end of the body. The angle of inward convergence is about 60 degrees in the present instance. Thus, as the cover is pressed onto the hem 21', the lip 22 engages the surface 44 and bends the skirt 16 inwardly as shown in FIG. 11. Before the hem edge passes the surface 44, the lip 22 encounters and rides along the downwardly diverging surface 45 of the outer skirt and into the groove between the walls 34', 35'. In the continued movement and as the hem edge is presented to the upper bead surface 43, the skirt 11 expands moving the bead surface 43 outwardly beneath the hem edge 13. Downward pressure on the cover is continued until the lip 22 of the hem becomes fully seated and wedged in between the walls 34, 35 during which the skirt continues to expand moving the bead surface 43 farther across the hem edge (FIG. 9). The parts are dimensional so that the final engagement between the hem edge 18' and the bead is intermediate the edges of the surface 43, this position varying somewhat with dimensional variations in the interengaging parts. Thus, the bead always interlocks effectually with the exposed hem edge 18 so as to hold the cover securely on the container body with opposite sides of the hem sealed tightly against the surfaces 34', 35 of the outer and inner skirts 36 and 11'.

In the high production manufacture of the plastic and metal parts of the above character, there may be dimensional variations of sufficient magnitude to prevent attainment of the desired uniform sealing pressure between, the hem and the opposed surfaces of the cover skirts of all containers. To compensate automatically for such variations and always insure optimum sealing of the cover around the body lip, the invention, in another of its aspects, contemplates a modification of the contour of the downwardly diverging surface 43 of the bead 16' as shown in FIGS. 13 to 17 so that the edge 18' of the shoulder 13 engages the bead 16' only at points spaced around the top surface of the bead thus allowing the hem edge 13 to penetrate the top of the bead to different depths at these points after the hem lip 22 has become seated and properly wedged in between the skirt surfaces 34', 35'.

In the present instance such points of engagement between the hem edge and the bead are defined by nibs 51 molded integral with and upstanding from the bead surface 43. Herein, the nibs take the form of ribs upstanding from and extending across the full radial Width of the bead surface 43. All are of substantially the same crosssection with opposite sides 52 diverging from the uppermost edge 54 toward the bead surface ferent degrees of resistance to penetration by the hem edge 18 in the final assembled position of the cover on the container body. Herein and as shown in FIGS. 14, 15, the ribs are ofgenerally rounded cross-section, for eX- ample one-eighth inch radius, are about one-eighth of an inch wide and .010 of an inch high, and are inclined at 43 to offer difthese being spaced equidistantly apart with the terminal ribs similarly spaced from the corners of the cover.

materially by the presence of the nibs.

In pressing the cover shown in FIGS, 13 and 14 onto the hemmed end of the body 12', the lip 22 cams the skirt 16' outwardly until the outer ends 53 of the nibs 51 pass the hem edge 18'. Then the skirt begins to contract and, in the continued sealing contact with the skirt surfaces 34', 35'. At this time, the movement of the nibs across the edge 18' is interrupted and the edge bites into the top of the nibs to a dimensions. Thus, the cover and hem are of the intended dimensions, the edge 18 will engage and penetrate the nibs as shown in FIG. 16. Between the nibs, the edge 18 will normally be spaced above the bead surface 43 as shown in FIG. 17.

the entire periphery of the cover.

It will be apparent from the foregoing that the second depending skirt 36 (FIGS, 1 to 3) or 36' (FIGS. 8 to 17) performs several important functions. First, it forms a lateral backing which acts to hold the hem in proper position relative to the skirt 11' and thus insuring that the hem edge 18' will remain properly interlocked and in biting engagement with the head 16'. Secondly, its surface 34 coacts with the surface 35' of the inner skirt 11 to provide for wedging and pressure seating of the hem against two opposed surfaces 34 35'. Sealing pressure of substantial magnitude around the two surfaces is facilsubstantially abutting one skirt and engaging the hold the hem edge in said head surface.

closed end portion of the hem to permanent biting engagement with skirt depending from said cover and laterally spaced from said first skirt to engage the end of said. tube and hold said edge in permanent biting engagement with the upwardly facing surface of said bead, the opposed surfaces of said two skirts above said bead forming a downwardly openof said skirts.

5. A container as defined in claim 2 shoulder is the edge of a stantially wider than it is in which said relatively flat hem which is subthick.

ing of said shoulder from said lip is several times the thickness of the lip.

7. A container as defined in claim 5 in which the Wall of said tube opposite said der for biting bead.

across and beneath said shoulder by virtue of the relative resiliency of said skirt and said lip, said head having an upwardly facing and downwardly inclined frusto-conical surface engaging said sharp edge with the latter digging into and interlocking with the softer plastic of said surface, and a peripherally continuous second skirt depending from said cover and laterally spaced from said first skirt to engage the end of said tube and hold said edge in permanent biting engagement with the upwardly facing surface of said head, the opposed surfaces of said two skirts above said head forming a downwardly opening groove into which said lip of said body is seated, the opposed surfaces of said two skirts above said bead converging upwardly and pinching said lip between them at points spaced from the upper closed end of the groove to provide tight seals around the tube end on the inner and outer sides thereof.

10. A container having, in combination, a body comprising a sheet metal tube, a cover of resilient plastic substantially abutting one end of the tube and having a laterally flexible depending peripheral skirt telescoped with said tube end, and means securing said cover onto the tube end comprising an end portion of said tube bent laterally and then reversely to define a lip of curved crosssection terminating in an edge spaced longitudinally from said lip and providing an exposed inwardly and axially facing shoulder, a bead integral with said skirt adjacent the lower edge thereof urged laterally across said shoulder by virtue of the resiliency of said skirt, a plurality of ribs upstanding and extending across the top of said bead at points spaced around the periphery of said skirt, the upper edges of said ribs being skirt to the free edge of said bead so as to engage said shoulder and hold the intervening portions of the shoulder out of engagement with said bead, and a second skirt depending from said cover and engaging the side of said inclined downwardly from said (3 es tube end opposite said first skirt to hold said shoulder in permanent engagement with said rib edges.

11. A container as defined in claim 10 in which the surfaces of opposite sides of each of said ribs diverge downwardly toward the top surface of said bead whereby to allow for different degrees of penetration of said shoulder in the different ribs.

12. A container having, in combination, a body comprising a sheet metal tube having an end portion bent laterally and then reversely to form a lip of arcuate crosssection at the end of the tube and a downwardly facing shoulder spaced longitudinally from said lip, a cover of resilient plastic material having two laterally spaced and flexible skirts depending therefrom and defining between them a peripheral and downwardly opening groove receiving said lip with the lip wedged in between the opposed surfaces of said skirts, a bead integral with one of said skirts and underlying said shoulder, and a plurality of nibs integral with and upstanding from the upper side of said bead and permanently engaging said shoulder to hold said lip wedged into said groove.

13. A container as defined in claim 12 in which each of said nibs comprises a rib having downwardly diverging sides and inclined downwardly and across said head for engagement with said shoulder at different points along its top edge depending on dimensional variations in said groove and the spacing of said shoulder from said lip. 

1. A CONTAINER HAVING IN COMBINATION, A BODY COMPRISING A SHEET METAL TUBE, A COVER OF RESILIENT PLASTIC SUBSTANTIALLY ABUTTING ONE END OF THE TUBE AND HAVING A PREFORMED LATERALLY FLEXIBLE DEPENDING PERIPHERAL SKIRT TELESCOPED WITH THE END PORTION OF SAID TUBE, AND MEANS SECURING THE COVER AND TUBE TOGETHER COMPRISING A PREFORMED RELATIVELY FLAT METAL HEM AT SAID TUBE END INCLUDING A PERIPHERAL FLANGE BENT LATERALLY AND THEN REVERSELY TO PROJECT ALONG AND LIE CLOSELY ADJACENT ONE SIDE SURFACE OF THE TUBE AND TERMINATING IN AN EDGE SPACED LONGITUDINALLY FROM THE TUBE END, THE PORTION OF SAID BODY BELOW SAID HEM BEING OFFSET RADIALLY FROM SAID HEM SO AS TO EXPOSE THE HEM EDGE AND THUS INCREASE THE EFFECTIVE WIDTH 